Artificial marble production device and artificial marble produced using same

ABSTRACT

The present invention provides an apparatus for manufacturing artificial marble, which includes a granite soil storage unit configured to supply a granite soil by storing, drying, and heating it, a granite soil heating unit configured to heat the granite soil supplied from the granite soil storage unit, a resin storage unit configured to store a thermoplastic polyurethane (TPU) resin maintained in a solid phase at room temperature, a mixing-transporting unit configured to accommodate the TPU resin and the heated granite soil therein and then melting and mixing them to produce and simultaneously transport an artificial marble slurry, a material guide unit configured to guide the granite soil and the TPU resin into the mixing-transporting unit, a discharge unit configured to discharge the artificial marble slurry mixed in the mixing-transporting unit by a certain amount, a mold supply unit configured to continuously supply a mold for accommodating and molding the artificial marble slurry therein, a mold guide unit configured to guide the mold supplied from the mold supply unit downward of the discharge unit to accommodate the artificial marble slurry in the mold, a forming unit configured to form an artificial marble by applying vibration and pressure to the artificial marble slurry accommodated in the mold, an extraction unit configured to extract the mold accommodating the artificial marble, and a lamination unit configured to laminate and store the mold extracted by the extraction unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/777,204 filed May 17, 2018 entitled “ARTIFICIALMARBLE PRODUCTION DEVICE AND ARTIFICIAL MARBLE PRODUCED USING SAME,” nowissued U.S. Pat. No. 10,858,288 and which is a 371 U.S. National StageApplication claiming priority to PCT/KR2017/006502 filed Jun. 21, 2017,which claims priority to Korean Patent Application No. 102016-0114269filed Sep. 6, 2016, which are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

The present invention relates to an apparatus for manufacturingartificial marble and an artificial marble manufactured using the same,and more particularly, to an apparatus for manufacturing artificialmarble, capable of continuously forming an artificial marble byindependently heating a granite soil and then mixing the heated granitesoil with a thermoplastic polyurethane (TPU) resin, and an artificialmarble manufactured using the same.

BACKGROUND ART

In general, there are different types of building stones, for example,bricks, blocks, tiles, marble, and granite. Here, concrete products suchas bricks or blocks are universally used since they are easy andeconomical in processing.

However, these products are used merely as fundamental materials and arelimited for building walls pursuing design values and stiffness, due torough surfaces and weak strength.

Meanwhile, marble, granite, and the like, which are natural stones, arewell used as materials for forming building walls since they have anexcellent design value according to the texture. However, there is alimit in quarrying these natural stones due to depletion of naturalresources and destruction of ecosystems, and for this reason, there isalways a possibility of causing a problem related to supply of rawmaterials.

Natural stone should be relatively thick, taking into account the safetyof constructed buildings and the safety of processed natural stone,which leads to an increase in cost. In addition, since it may bedifficult or impossible to process the natural stone and the shape andquality of the natural stone depend on the circumstances of producingdistricts, there are many limitations in designing and constructingbuildings.

Above all things, it is difficult to generally use this natural stonewhich price is expensive. Besides, stones which are discharged due toremoval or replacement and damage of buildings are discarded or leftuntreated, which brings about environmental pollution and senselesswaste of available resources.

Accordingly, many techniques for manufacturing artificial stone havebeen developed and used in recent years.

Artificial marble is generally manufactured by mixing an acrylic polymerresin with a large amount of powdered mineral fillers, marble chips,various kinds of additives, curing initiators, pigments, etc. to producea slurry-phase mixture, pouring the mixture into a mold or the like,curing the poured mixture in an appropriate curing device to produce asheet-shaped semi-finished product, and then processing thesemi-finished product through edge trimming and surface polishing. Thisartificial marble is an imperforate material with identical surface andinterior, and may be easily cut, polished, bent with heat, and bondedwith adhesive while being strong. Thus, the artificial marble is inincreasing demand as building interior materials such as upper sinks forkitchen, various kinds of counters, washstands, and wall materials.

For example, Korean Patent Application Publication No. 1999-0061711discloses an apparatus for am acryl based artificial marble platecontinuously by using a hardening apparatus, capable of curing a productby adjusting the width thereof using only a set of steel belts.

However, the raw material mixture injected into the apparatus isproduced by mixing 100 parts by weight of acrylic resin syrup with 110to 300 parts by weight of mineral filler, a small amount of dispersingagent, a cross-linking agent, a photostabilizer, and a pigment in astirring mixer, and deaerating it under vacuum.

Korean Patent Application Publication No. 10-2012-0006178 discloses anapparatus for manufacturing artificial stone for construction, capableof manufacturing an artificial stone by adding a hardener, teabagpowder, a dye, and water to a primary mixture which is obtained bymixing magnesia cement, anhydrous gypsum, limestone, and snowflake stoneto produce a secondary mixture, and then forming and curing thesecondary mixture.

Korean Patent Application Publication No. 10-2011-0091610 discloses asystem for manufacturing artificial-stone interior/exterior sheets,capable of continuously manufacturing an interior/exterior sheet in theform of artificial stone using cement mortar as a main material withouta mold.

Korean Patent No. 10-1241777 discloses an inorganic artificial marbleand a composition for inorganic artificial marble.

This is a technique for producing artificial marble slurry by mixing 10parts by weight of inorganic powder, which is obtained by baking kaolinand brushite in a 350-furnace and collecting and pulverizing it, with 90parts by weight of a quartz-silica chip, and injecting 30 parts byweight of an acid activator of pH 1 thereinto.

The acid activator is adapted to have a pH of 1 by producing an aqueoussolution such that the solid content of sodium silicate and potassiumsilicate is 55 parts by weight, and adding hydrochloric acid thereto.

Korean Patent Application Publication No. 10-2004-0056647 discloses amethod for continuously producing artificial marble and an apparatususing the same, capable of continuously manufacturing an artificialmarble such that curing reactant is not bent by a heating mean providedto heat the upper and lower surface of a raw material mixture at thesame temperature.

That is, this is a technique for producing a raw material mixture bymixing unsaturated ester resin, acrylate resin, or methacrylate resin asa thermoplastic resin, aluminum hydroxide, silicate, or magnesium oxideas a filler, a peroxide or perester compound as a reaction initiator,and an acrylate compound as a cross-linking agent.

The above techniques are not preferred for safety in that since thecomponents harmful to human bodies, such as hardeners, reactioninitiators, and cross-linking agents, are contained in the productmanufactured thereby, their release increases rapidly particularly whenthe temperature rises.

In addition, the thermoplastic resin may not be recycled when it is usedas a binder, and the solvent added to increase fluidity during moldingalso causes environmental hormones and toxic substances. Hence, it mayadversely affect the health of children or elderly people with low levelof immunity.

In addition, it is difficult to apply the products manufactured by theconventional techniques to a flooring material since the product has lowdurability and does not have elasticity and permeable functions due tohigh hardness.

For example, desertification is accelerated due to forest destruction,wrong urbanization, or the like in modern times and rainwater isartificially drained through drainage channels in cities, which leads tosevere destruction of climatic environment. Therefore, road pavementmust be performed using a flooring material with permeability forrecovery of water circulation around the city.

However, since the products manufactured by the conventional techniquesdo not have permeable functions and has low shock-absorbing power, it isimpossible to apply the products to a flooring material or the like forwalking or it is difficult to change the use of the products in variousways.

In order to resolve these problems, Korean Patent No. 10-1191092discloses a permeable block using high molecular polymer, which hasimproved strength and elasticity and permeability by using a highmolecular polymer instead of a cement mixture.

In more detail, the high molecular polymer is produced by mixing apolymethyl methacrylate (PMMA) or urethane-acrylate resin and apolymerization initiator, and the polymerization initiator is anecessary component that cures the PMMA or urethane-acrylate resin bypolymerization therewith.

Accordingly, there is a problem in that the permeable block necessarilyrequires the polymerization initiator which is harmful to human bodiesand brings about serious environmental pollution because it is difficultto recycle the permeable block after being cured.

Moreover, in the conventional techniques, there is no artificial marblemanufactured by adopting a thermoplastic polyurethane (TPU) resin, whichis harmless to human bodies, has elastic force, and is in a solid phaseat room temperature. In addition, they disclose only a continuousforming process while the product has a permeable function, withoutsuggesting a specific embodiment for how different materials are mixedin the apparatus for manufacturing the same. For this reason, it isdifficult to check whether or not permeability performance isimplemented in practice.

CITATION LIST

Korean Patent Application Publication No. 1999-0061711

Korean Patent Application Publication No. 10-2012-0006178

Korean Patent Application Publication No. 10-2011-0091610

Korean Patent No. 10-1241777

Korean Patent Application Publication No. 10-2004-0056647

Korean Patent No. 10-1191092

SUMMARY OF INVENTION Technical Problem

The present invention has been made in view of the above-mentionedproblems, and an object thereof is to provide an apparatus formanufacturing artificial marble, capable of continuously forming anartificial marble in the form of a sheet by independently heating agranite soil and then mixing the heated granite soil with athermoplastic polyurethane (TPU) resin, and an artificial marblemanufactured using the same.

Another object of the present invention is to provide an apparatus formanufacturing artificial marble, capable of continuously forming asheet-shaped artificial marble having high safety since it does notcause environmental hormones and toxic substances, and simultaneouslyhaving elasticity and drainage capability by using a thermoplasticpolyurethane (TPU; CAS No. 75701-44-9) resin as a binding material,which is a solid-phase elastic body at room temperature, without using athermosetting polyurethane (PU) resin produced by mixing a solvent withcement mixed with water used as a conventional binding material, anacrylic, unsaturated polyester, or epoxy binder, or a polyurethane (PU;CAS No. 9009-54-5) material, which is in a liquid phase at roomtemperature, as a binding material, and by securing a flow behaviorrequired for mixing by applying heat to the pure thermoplasticpolyurethane resin, unlike a conventional binding material whichrequires a reaction initiator, a hardener, or a solvent to secure a flowbehavior, thereby enabling to continuously manufacture the artificialmarble to be used in various manners for interior/exterior materials forbuilding or artificial stone for permeable flooring materials, and anartificial marble manufactured using the same.

A still another object of the present invention is to provide anapparatus for manufacturing artificial marble, capable of continuouslyforming a sheet-shaped artificial marble having a beautiful appearanceand suppressing generation of radiant heat, and an artificial marblemanufactured using the same. Here, when mixing a TPU resin as thermoplastics with a granite soil as aggregate with weak strength, it doesnot use a screw extrusion technique for applying a high temperature anda strong shearing force to a material to extrude the material at highpressure by melting and mixing, which is a conventional techniqueuniversally used when processing thermo plastics. Accordingly, thepresent invention accommodates the heated granite soil and thethermoplastic polyurethane resin together, and melts and mixes themthrough rolling by the self-weight of the accommodated material toproduce an artificial marble slurry, and at the same time, continuouslytransports the artificial marble slurry, which is in a high-viscosityfluid state causing consumption of large amount of energy in a separatetransport process, to simplify a handling process and minimize anexternal force applied to the granite soil, through the application of amixing-transporting technique capable of minimizing the damage andabrasion of the granite soil. In addition, by washing the granite soilto remove fine powder from the surface thereof, the porous rough surfaceof a granite soil particle serves as a hook, and the TPU resin servingas a rope is strongly bonded to the surface of the granite soilparticle. It is also possible to increase penetration of the TPU resinby expansion of fine pores of the heated granite soil. Thus, it ispossible to expect high durability in molding completion and increasesound absorption/vibration absorption and thermal insulation effects byforming pores between adjacent granite soils, leading to reducedmanufacturing costs by using the granite soil, which is cheap because oflow availability due to weak strength and is easily supplied, as a mainmaterial, and to maintain the intrinsic color and texture of the naturalgranite soil.

A further object of the present invention is to provide an apparatus formanufacturing artificial marble, capable of continuously forming arecyclable artificial marble in the form of a sheet by inserting abroken artificial marble together when mixing a thermoplasticpolyurethane resin and a granite soil, in such a way to adopt the TPUresin, make the curing time of an artificial marble slurry slow usingthe characteristic of thermoplastic resin, which the curing time ofmelting by heat and then cooling is much slower compared to other thermoplastics, and thermal energy accumulated in the independently heatedgranite soil so as to secure the time required to maintain a moltenstate necessary for sufficient bonding as needed for processing, and tomanufacture the artificial marble using only the thermoplasticpolyurethane resin and the granite soil without using other additives,and an artificial marble manufactured using the same.

Solution to Problem

An apparatus for manufacturing artificial marble according to an aspectof the present invention includes a granite soil storage unit configuredto supply a granite soil by storing, drying, and heating it, a granitesoil heating unit configured to heat the granite soil supplied from thegranite soil storage unit, a resin storage unit configured to store athermoplastic polyurethane (TPU) resin maintained in a solid phase atroom temperature, a mixing-transporting unit configured to accommodatethe TPU resin and the heated granite soil therein and then melting andmixing them to produce and simultaneously transport an artificial marbleslurry, a material guide unit configured to guide the granite soil andthe TPU resin into the mixing-transporting unit, a discharge unitconfigured to discharge the artificial marble slurry mixed in themixing-transporting unit by a certain amount, a mold supply unitconfigured to continuously supply a mold for accommodating and moldingthe artificial marble slurry therein, a mold guide unit configured toguide the mold supplied from the mold supply unit downward of thedischarge unit to accommodate the artificial marble slurry in the mold,a forming unit configured to form an artificial marble by applyingvibration and pressure to the artificial marble slurry accommodated inthe mold, an extraction unit configured to extract the moldaccommodating the artificial marble, and a lamination unit configured tolaminate and store the mold extracted by the extraction unit.

The granite soil storage unit may have a dehumidification function forremoving water from the granite soil.

The granite soil heating unit may include a low temperature portionhaving a heating temperature of 100 to 300° C., an intermediatetemperature portion having a heating temperature of 150 to 350° C., anda high temperature portion having a heating temperature of 200 to 400°C., and the granite soil may be gradually heated to a temperature of 150to 250° C.

The mixing-transporting unit may form the artificial marble slurry bymelting and mixing the granite soil and the TPU resin through rolling byself-weight, thereby minimizing damage and abrasion of the granite soil.

The material guide unit may include a granite soil flow pipe for guidingthe granite soil into the mixing-transporting unit, and a resin flowpipe for guiding the TPU resin into the mixing-transporting unit in astate in which it is partitioned from the granite soil flow pipe.

The discharge unit may be narrowed in internal size toward its lowerportion to collect the artificial marble slurry supplied from themixing-transporting unit by a certain amount and then continuouslydischarge it by self-weight, and a pressure of 0.1 to 1 kgf/cm2 may beapplied to the artificial marble slurry during discharge.

The mold guide unit may move the artificial marble slurry, which isdischarged from the discharge unit, at a downward angle of 20 to 35° toguide it into the mold.

The mold guide unit may have a temporary-forming part provided at oneside thereof to pressurize and form the artificial marble slurry that isdischarged from the discharge unit and accommodated in the mold.

The forming unit may laminate a plurality of molds accommodating theartificial marble slurry to apply a load of 0.1 kgf/cm2 to 1 kgf/cm2 toa mold located at the lowermost position while providing vibration tothe mold, the extraction unit may extract the mold located at thelowermost position, and a mold laminated at the uppermost position maybe extracted by the extraction unit in a state in which the artificialmarble is completed after 5 to 20 minutes.

The extraction unit may extract the mold located at the lowermostposition.

The forming unit may include a lamination space that is open at aportion of a side surface thereof and its upper portion for laminationof the plurality of molds, a lifter configured to rectilinearlyreciprocate in a vertical direction outside the lamination space, a loadremoval part extended and reduced in a direction of the molds andcoupled to one side of the lifter to remove a load applied to thelowermost mold by vertical interlocking, a pedestal supporting the moldstransported by the loader to laminate the molds in the lamination space,and a vibration generator for providing vibration to the molds.

The lamination unit may accommodate a rack for laminating the pluralityof molds, and the rack may be moved up and down by an elevation device.

A rack supply unit may be provided in the vicinity of the mold supplyunit to supply the rack accommodating therein the plurality of moldsfrom which the artificial marble is separated into the mold supply unit.

In the artificial marble according to the present invention, the TPUresin may be coated on an outer surface of the granite soil, and thegranite soil and a granite soil adjacent thereto may be spaced apartfrom each other to form a pore.

The granite soil may be protected by the TPU resin when an externalforce is applied thereto, and the TPU resin may generate an elasticforce.

Advantageous Effects of Invention

According to the present invention, it is possible to continuously formand manufacture an artificial marble in the form of a sheet byindependently heating a granite soil and then mixing the heated granitesoil with a thermoplastic polyurethane (TPU) resin.

Thus, it is possible to reduce costs and produce the artificial marblein quantity.

Since the TPU resin, which is a solid-phase elastic body at roomtemperature, is used as a binding material in the present invention, itis possible to secure a flow behavior required for mixing by applyingheat to the pure TPU resin, unlike a conventional binding material whichrequires a reaction initiator, a hardener, or a solvent to secure a flowbehavior. Therefore, the artificial marble can have high safety since itdoes not cause environmental hormones and toxic substances, andsimultaneously have elasticity and drainage capability. Consequently,the artificial marble can be used in various manners forinterior/exterior materials for building or artificial stone forpermeable flooring materials.

In the case of mixing the TPU resin with the granite soil, it ispossible to produce an artificial marble slurry by melting and mixingthrough rolling by the self-weight of the material, and at the same timeto continuously transport the artificial marble slurry, which is in ahigh-viscosity fluid state causing consumption of large amount of energyin a separate transport process, to simplify a handling process andminimize an external force applied to the granite soil, through theapplication of the mixing-transporting technique capable of minimizingthe damage and abrasion of the granite soil. In addition, since theporous rough surface of the granite soil particle serves as a hook bywashing the granite soil to remove fine powder from the surface of thegranite soil particle, and the TPU resin serving as a rope is stronglybonded to the surface of the granite soil particle, it is possible toincrease penetration of the TPU resin by expansion of fine pores of theheated granite soil and to expect high durability in molding completion.

It is possible to increase sound absorption/vibration absorption andthermal insulation effects by forming pores between the adjacent granitesoils, to reduce manufacturing costs by using the granite soil, which ischeap because of low availability due to weak strength and is easilysupplied, as a main material, and to maintain the intrinsic color andtexture of the natural granite soil. Therefore, it is possible tomanufacture the artificial marble having a beautiful appearance andsuppressing generation of radiant heat.

It is possible to manufacture a recyclable artificial marble byinserting a broken artificial marble together when mixing the TPU resinand the granite soil, in such a way to adopt the TPU resin, make thecuring time of an artificial marble slurry slow using the characteristicof thermoplastic resin, which the curing time of melting by heat andthen cooling is much slower compared to other thermo plastics, andthermal energy accumulated in the independently heated granite soil soas to secure the time required to maintain a molten state necessary forsufficient bonding as needed for processing, and to manufacture theartificial marble using only the TPU resin and the granite soil withoutusing other additives.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a photograph illustrating an external appearance of anartificial marble according to the present invention.

FIG. 2 is a schematic picture illustrating bonding action betweengranite soil and thermoplastic urethane resin which are main componentsof the artificial marble according to the present invention.

FIG. 3 is a perspective view illustrating a configuration of anapparatus for manufacturing artificial marble according to the presentinvention.

FIG. 4 is a perspective view illustrating a configuration of a granitesoil storage unit which is one component in the apparatus formanufacturing artificial marble according to the present invention.

FIG. 5 is an exploded perspective view illustrating a configuration of agranite soil heating unit which is one component in the apparatus formanufacturing artificial marble according to the present invention.

FIG. 6 is a perspective view illustrating the coupling between a resinstorage unit and a material guide unit which are components in theapparatus for manufacturing artificial marble according to the presentinvention.

FIG. 7 is a perspective view illustrating an internal structure of amixing-transporting unit which is one component in the apparatus formanufacturing artificial marble according to the present invention.

FIG. 8 is a schematic view illustrating arrangement and operation of thematerial guide unit and the mixing-transporting unit which arecomponents in the apparatus for manufacturing artificial marbleaccording to the present invention.

FIG. 9 is a perspective view illustrating arrangement of a dischargeunit, a mold guide unit, and a temporary-forming part which arecomponents in the apparatus for manufacturing artificial marbleaccording to the present invention.

FIG. 10 is a perspective view illustrating arrangement of a loader and aforming unit which are components in the apparatus for manufacturingartificial marble according to the present invention.

FIG. 11 is a partially enlarged perspective view illustrating theforming unit which is one component in the apparatus for manufacturingartificial marble according to the present invention.

FIG. 12 is a perspective view illustrating operation of a pedestal ofthe forming unit which is one component in the apparatus formanufacturing artificial marble according to the present invention.

FIG. 13 is a perspective view illustrating arrangement of a laminationunit and an extraction unit which are components in the apparatus formanufacturing artificial marble according to the present invention.

FIG. 14 is a perspective view illustrating arrangement of a mold supplyunit and a rack supply unit which are components in the apparatus formanufacturing artificial marble according to the present invention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the configuration of an artificial marble according toexemplary embodiments of the present invention will be described withreference to FIG. 1 .

Prior to the description, it is noted that the terms and words used inthe specification and claims should not be construed as being limited tocommon or dictionary meanings but instead should be understood to havemeanings and concepts in agreement with the spirit of the presentinvention based on the principle that an inventor can define the conceptof each term suitably in order to describe his/her own invention in thebest way possible.

Accordingly, the embodiment described in the specification and theconstruction shown in the drawings are nothing but one preferredembodiment of the present invention, and it does not cover all thetechnical ideas of the invention. Therefore, it should be understoodthat various changes and modifications which can substitute for theembodiments may be made at the time of filing the present application.

FIG. 1 is a photograph illustrating an external appearance of anartificial marble according to the present invention.

As illustrated in the drawing, the artificial marble, which isdesignated by reference numeral 1, according to the present inventionhas an elastic force to absorb shocks applied from the outside and isformed to have a variety of sheet shapes.

The artificial marble 1 is configured to have permeability by poresformed therein.

To this end, the artificial marble 1 includes a granite soil and athermoplastic polyurethane (TPU) resin.

That is, the artificial marble 1 is formed using the granite soil(decomposed granite soil), which is formed by weathering of granite andgranite gneiss which account for more than 55% of rock distributed inthe country, and the TPU resin, which is a non-toxic material with noemission of harmful substances and has high water resistance,oil/chemical resistance, and weather resistance, and excellentmechanical properties, as a binding material.

The granite soil is limitedly used for building since it has weakstrength while being easily supplied and being cheap, but the granitesoil in the present invention is formed to have enhanced strength bycoating the TPU resin on the outer surface of the granite soil and tohave permeability by pores formed in such a way to bond the TPU resincoated on the outer surface of the granite soil.

The artificial marble 1 has coating adhesion secured by mixing andcoating the washed granite soil, from which water is removed, with theTPU resin so that the TPU resin permeates to microcracks formed on thesurface of the granite soil.

In more detail, the granite soil is used in the state in which finepowder is removed from the particles of the granite soil by washing, andis mixed with the TPU resin in the state in which it is gradationallyheated to prevent cracks so that the surface pores of the granite soilare expanded.

Accordingly, to increase a binding force, the TPU resin deeply permeatesinto the surface pores of the granite soil and the rough surface of thegranite soil is bounded to the TPU resin in a manner that a rope islatched to a hook (see FIG. 2 ).

Hereinafter, a configuration of an apparatus for manufacturingartificial marble 100 to manufacture the artificial marble 1 will bedescribed with reference to FIG. 3 .

FIG. 3 is a perspective view illustrating the configuration of theapparatus for manufacturing artificial marble 100 according to thepresent invention.

The configuration of the apparatus for manufacturing artificial marble100 will be described in sequence according to the manufacturing processin which granite soil and TPU resin move.

First, the apparatus for manufacturing artificial marble 100 includes agranite soil storage unit 102 that stores granite soil. The granite soilstorage unit 102 accommodates a large amount of granite soil therein anddischarges the granite soil downward as occasion demands. As illustratedin FIG. 4 , the granite soil storage unit 102 has an opening portion 103formed in the lower portion thereof to be selectively opened fordischarging the granite soil stored therein in the downward direction.

The granite soil storage unit 102 has a hot-air blower provided thereinto supply heat to the internal space of the granite soil storage unitand dry the granite soil, so that the hot-air blower performsdehumidification and heating functions.

The hot-air blower heats the granite soil at a temperature of 80 to 120°C. and dries it to have a moisture content of 1 to 3%.

A granite soil heating unit 104 is provided beneath the granite soilstorage unit 102. The granite soil heating unit 104 heats the warmgranite soil, from which water is removed, at high temperature whiletransporting the granite soil.

The granite soil heating unit 104 will be described in more detail withreference to FIG. 5 . The granite soil heating unit 104 includes aconveyor 105 and a heating furnace 106.

The conveyor 105 is of a track type to rotate at a constant speed, andtransports the granite soil placed on the upper surface thereof. Theheating furnace 106 generates heat in the inward direction to heat thegranite soil transported by the conveyor 105. The heating furnace 106gradually increases a heating temperature to prevent the damage of thegranite soil due to rapid heating while the granite soil is transportedby the conveyor 105.

That is, the heating furnace 106 is divided into a low temperatureportion, an intermediate temperature portion, and a high temperatureportion from the rear end thereof to the front end thereof, to graduallyincrease a heating temperature. In more detail, the low temperatureportion heats the interior of the heating furnace 106 at a temperatureof 100 to 300° C., the intermediate temperature portion heats it at atemperature of 150 to 350° C., and the high temperature portion heats itat a temperature of 200 to 400° C.

Thus, since the granite soil is gradually heated during transport alongthe conveyor 105, it is possible to previously prevent the damage orcracking of the granite soil due to rapid heating.

In an embodiment of the present invention, the conveyor 105 transportsthe granite soil at a speed of 5 to 20 kg/min and the heating furnace106 generates heat so that the granite soil has a moisture content of0.01 to 0.5% and a temperature of 180 to 250° C.

If the moisture content of the granite soil exceeds 0.5%, the granitesoil may be cracked due to a reduction in adhesion even though it iscoated with the TPU resin. Therefore, the granite soil is preferablycontrolled to have a moisture content equal to or less than 0.5%.

If the granite soil is heated at a temperature less than 180° C., it isdifficult to mix the granite soil with the TPU resin. If the granitesoil is heated at a temperature more than 250° C., the mechanicalproperties of the TPU resin may be damaged when the granite soil comesinto contact with the TPU resin.

Thus, the granite soil is preferably controlled to be heated at atemperature of 180 to 250° C.

When the granite soil is heated at a temperature of 180 to 250° C., thegranite soil expands in volume and the microcracks on its surface areexpanded. The expanded microcracks allow the molten TPU resin to easilypermeate into the granite soil, thereby enabling an increase in thebinding force and strength of the granite soil and the TPU resin.

Referring to FIGS. 3 and 6 , a resin storage unit 110 is provided infront of the granite soil heating unit 104. The resin storage unit 110accommodates a TPU resin therein and discharges it downward as occasiondemands.

The resin storage unit 110 includes a heating device or a drying devicetherein to control the TPU resin accommodated therein to have a moisturecontent of 0.01 to 0.5%.

A material guide unit 120 is installed beneath the resin storage unit110. The material guide unit 120 guides the TPU resin flowing down fromthe resin storage unit 110 in the rearward direction when viewed in FIG.6 , and then forces its flow in the forward and downward directionagain.

To this end, the material guide unit 120 is provided therein with ascrew 124 that is rotated by rotational force received from a guidemotor 122 to force the flow of the TPU resin in the rearward direction,and the outer periphery of the screw 124 is surrounded by a resin guidepipe 126.

Meanwhile, the rear end of the resin guide pipe 126 communicates with aresin flow pipe 127. The resin flow pipe 127 serves to accommodate theTPU resin, which forcibly flows rearward by the screw 124 and dropsdownward, and guides it forward and downward again.

A granite soil flow pipe 128 is provided beneath the resin flow pipe127. The granite soil flow pipe 128 is partitioned from the resin flowpipe 127, and serves to guide the granite soil accommodated thereinto inthe same direction as the flow direction of the resin.

Accordingly, the granite soil flow pipe 128 is largely open upward atthe rear end thereof, and is placed to accommodate the granite soildropping through the opening portion 103.

The granite soil and TPU resin guided forward, in the state in whichthey are separated from each other by the material guide unit 120, areinserted into a mixing-transporting unit 130. The detailed configurationof the mixing-transporting unit 130 the coupling relationship betweenthe mixing-transporting unit 130 and the material guide unit 120 will bedescribed with reference to FIGS. 7 and 8 .

FIG. 7 is a perspective view illustrating the internal structure of themixing-transporting unit 130 which is one component in the apparatus formanufacturing artificial marble 100 according to the present invention.FIG. 8 is a schematic view illustrating the arrangement and operation ofthe material guide unit 120 and the mixing-transporting unit 130 whichare components in the apparatus for manufacturing artificial marble 100according to the present invention.

As illustrated in the drawings, the ends of the resin flow pipe 127 andgranite soil flow pipe 128 are inserted into a mixer 132, and the mixer132 is rotated by a motor for mixing and transporting 134.

The mixer 132 has a predetermined space defined therein to be able toaccommodate the granite soil and the TPU resin, and has a heating means136 formed on the outer peripheral surface thereof to be able to mix andtransport the granite soil and TPU resin accommodated therein whileheating them.

In an embodiment of the present invention, the heating means 136generates heat to increase the inner temperature of the mixer 132 to atemperature of 250 to 380° C.

The mixer 132 has a plurality of blades 138 formed therein, asillustrated in FIG. 8 , to help to more efficiently mix the granite soiland the TPU resin.

That is, the blades 138 with a thin plate shape stands continuously in aspiral form on the inner peripheral surface of the mixer 132.

The mixer 132 rotates at a low speed such that an artificial marbleslurry obtained by mixing the molten TPU resin and the granite soil isnot moved upward by viscosity during rotation.

Accordingly, the artificial marble slurry is transported in a spiraldirection in which the blades 138 are formed (in the right direction inFIG. 8 ) while rolling by self-weight along the separated space betweenthe blades 138, more specifically between the blades 138 located on thebottom of the mixer 132.

This is to prevent the granite soil from dropping in the mixer 132 tominimize the abrasion and damage of the granite soil and efficiently mixthe granite soil with the TPU resin, and to move the artificial marbleslurry, which is in a high-viscosity fluid state causing consumption oflarge amount of energy in handling, to a next process for both of mixingand forming without having a separate transport process.

The mixer 132 is open at the rear thereof, and the artificial marbleslurry mixed in the mixer 132 is discharged rearward and then collectedin a discharge unit 140.

The discharge unit 140 is arranged behind the mixer 132. The dischargeunit 140 serves to guide and discharge the collected artificial marbleslurry, which is in a high-viscosity semisolid state causing consumptionof large amount of energy in the process of collecting and handling theartificial marble slurry, by the self-weight thereof in the downwarddirection without using a separate extrusion device. The discharge unit140 is narrowed in internal size toward the lower portion thereof, andserves to uniformly control an amount of the collected artificial marbleslurry to maintain the discharge unit at a pressure of 0.1 to 1 kgf/cm2.

A mold guide unit 150 is located beneath the discharge unit 140, asillustrated in FIG. 3 .

Hereinafter, the detailed configuration of the mold guide unit 150 willbe described with reference to FIG. 9 .

FIG. 9 is a perspective view illustrating the arrangement of thedischarge unit 140, the mold guide unit 150, and a temporary-formingpart 152 which are components in the apparatus for manufacturingartificial marble 100 according to the present invention.

As illustrated in the drawing, the mold guide unit 150 is inclined at anangle of 20 to 35° in order to obliquely transport a square plate-shapedmold M, the interior of which is open upward, in the right direction,and to apply the artificial marble slurry throughout the mold M in auniform amount.

The mold guide unit 150 uses a conveyor belt applied thereto, and thedischarge unit 140 is located above the central portion of the moldguide unit 150.

The temporary-forming part 152 is arranged to the right from the lowerend of the discharge unit 140. The temporary-forming part 152 serves touniformly compact the artificial marble slurry, which is accommodated inthe mold M by dropping downward from the open lower end of the dischargeunit 140, to have a certain height, and temporarily forms the artificialmarble slurry in the form of a sheet by heating and pressing.

In an embodiment of the present invention, the temporary-forming part152 is configured in the form of a roller having a built-in heater.

The artificial marble slurry, which is temporarily formed in the form ofa sheet by the temporary-forming part 152 in the mold M, is transportedforward by a loader (see reference numeral 160 in FIG. 3 ). The detailedconfiguration of the loader 160 will be described with reference toFIGS. 10 to 12 .

FIG. 10 is a perspective view illustrating arrangement of the loader 160and a forming unit 170 which are components in the apparatus formanufacturing artificial marble 100 according to the present invention.FIG. 11 is a partially enlarged perspective view illustrating theforming unit 170 which is one component in the apparatus formanufacturing artificial marble 100 according to the present invention.FIG. 12 is a perspective view illustrating operation of a pedestal 176of the forming unit 170 which is one component in the apparatus formanufacturing artificial marble 100 according to the present invention.

As illustrated in the drawings, the loader 160 rectilinearlyreciprocates in the left and right direction to transport the mold M tothe left direction, is fixed to a frame 162, and adopts a cylinder forextending and reducing its length.

The loader 160 rectilinearly moves in the state in which it supports themold M thereon, to seat the mold M in the forming unit 170.

The forming unit 170 serves to form the temporarily-formed artificialmarble slurry accommodated in the mold M once more and complete theartificial marble 1, and can increase a density of the artificial marble1 by generating vibration and pressure at the same time.

The time required until the artificial marble slurry accommodated in themold M is perfectly cured while the mold M is laminated on the formingunit 170 and moves down to the lowermost position, and is extractedafter the completion of the molding is set as 5 to 20 minutes, takinginto account characteristics of the TPU resin, which is classified indifferent types of grades, and the curing time of which significantlyvaries depending on the grade.

That is, after the artificial marble slurry in the mold M placed at theuppermost position of the forming unit 170 is cured while graduallymoving down so that the artificial marble 1 is completed, the artificialmarble is located at the lowermost position and then extracted to theoutside by an extraction unit 180 after 5 to 20 minutes.

The forming unit 170 has support fixtures 171 formed to the left andright thereof while each is perforated therein in front and back, leftand right, and up and down directions for installation of a plurality ofparts therein. Each of the support fixtures 171 is maintained at acertain position, and has a lifter 172 moving up and down therein.

The lifter 172 moves up and down by extending and reducing in length ofa cylinder installed at the lower side of the lifter in the supportfixture 171.

A lamination space 173 is defined between the support fixtures 171. Thelamination space 173 is a space for lamination of the mold Maccommodating the artificial marble slurry, and is open at the lower andupper portions of the front surface thereof and at the edges at whichthe front surface thereof meets the left and right sides thereof.

Accordingly, when a plurality of molds M is laminated in the laminationspace 173, the molds M are in a state as in FIG. 10 , and the mold Mlocated at the lowermost layer from among the molds M laminated in thelamination space 173 is exposed at the front thereof.

A vibration generator 174 is arranged in the lower portion of thelamination space 173. The vibration generator 174 serves to form theartificial marble slurry inserted into the mold M to have a highdensity. The plurality of molds M laminated in the lamination space 173are simultaneously subjected to a load by self-weight as moving down,and it is therefore possible to improve a filling density together withthe vibration generated by the vibration generator 174.

Meanwhile, a load removal part 175 is arranged between the pair oflifters 172. The load removal part 175 is configured such that thelength thereof is extended and reduced in the direction facing thelifters 172. The end of the load removal part 175 is fitted to the moldM, thereby lifting a plurality of molds M when the lifters 172 move up.

That is, the load removal part 175 has a plurality of fittingprotrusions 178 formed in the direction facing each other as in FIG. 11, and the mold M has insertion grooves H formed in the outer edgethereof.

The number of the fitting protrusions 178 is one less than the number ofthe laminated molds M.

This is to lift remaining molds M except for the mold M located at thelowermost layer up from among the laminated molds M. While the number ofthe fitting protrusions 178 is one less than the number of molds M, thefitting protrusion 178 located at the lowermost position from among theplurality of fitting protrusions 178 is designed to be inserted into theinsertion groove H formed in the second mold M from the bottom.

Accordingly, when the lifters 172 are lifted up in the state in whichthe fitting protrusions 178 are inserted into the insertion grooves H,all of the plurality of molds M laminated in the lamination space 173are lifted up, except for the mold M located at the lowermost layer.

Through such an operation, the mold M located at the lowermost layer canbe extracted by the extraction unit 180 as illustrated in FIG. 11 .

Meanwhile, the pedestal 176 is further provided between the pair oflifters 172 as illustrated in FIG. 12 . The pedestal 176 is a componentfor seating the mold M transported by the loader 160 with safety throughthe upper portion of the lamination space 173.

That is, the pedestal 176 reciprocates and rotates by interlocking withthe cylinder, the length of which is extended and reduced, in the statein which it is coupled to the lifters 172, and supports the mold M byoperating such that the lower end of the pedestal is placed in the upperor outer side of the lamination space 173.

In more detail, when the mold M enters in the upper side of thelamination space 173 by the loader 160 in the state in which the lowerend of the pedestal 176 is located in the upper side of the laminationspace, the lower end of the pedestal 176 is maintained in the state inwhich it is located in the internal side of the lamination space 173 tosupport the lower surface of the mold M in the upward direction.

Accordingly, the pedestal 176 can prevent the mold M from dropping, andmay seat the mold M supported by the interaction with the lifters 172 inthe uppermost side of the lamination space 173.

Hereinafter, the detailed configuration of the extraction unit 180 willbe described with reference to FIG. 13 .

FIG. 13 is a perspective view illustrating the arrangement of alamination unit 184 and the extraction unit 180 which are components inthe apparatus for manufacturing artificial marble 100 according to thepresent invention.

As illustrated in the drawing, the extraction unit 180 extracts theplurality of molds M laminated in the lamination space 173 to theoutside of the lamination space 173. In an embodiment of the presentinvention, the extraction unit 180 adopts a cylinder and extracts themold M by grasping force generated when the length of the cylinder isextended.

The extraction unit 180 includes a mold cabinet 182 formed in the rearthereof to temporarily laminate and store the plurality of molds Mextracted from the lamination space 173. The mold cabinet 182 maytemporarily store the plurality of layered molds M and then transportthem to the left direction, and may force the transportation of themolds M by adopting a conveyor belt.

The lamination unit 184 is provided at the left end of the mold cabinet182. The lamination unit 184 may accommodate the molds M, which areextracted from the lamination space 173 by the extraction unit 180, in alaminated state in a rack (see reference numeral R in FIG. 3 ).

The configuration of the lamination unit 184 will be described indetail. The lamination unit 184 includes a rack accommodation part 185that accommodates a rack R, a support frame 186 that accommodates therack accommodation part 185 to support a load, and an elevation member187 that is extended and reduced in the height direction of the supportframe 186 and is coupled to the lower end of the rack accommodation part185 to move up and down the rack accommodation part 185.

Accordingly, when the length of the elevation member 187 is reduced inthe state as in FIG. 13 , the rack accommodation part 185 moves up andthe rack R accommodated in the rack accommodation part 185 is alsolifted up, thereby enabling the mold M transported to the left along themold cabinet 182 to be accommodated in the rack R.

In contrast, when the length of the elevation member 187 is extended,the rack accommodation part 185 moves down and the rack R accommodatedin the rack accommodation part 185 may be extracted to the left togetherwith the mold M as illustrated in FIG. 3 .

Meanwhile, the apparatus for manufacturing artificial marble 100includes a rack supply unit (see reference numeral 190 in FIG. 3 ). Thedetailed configuration of the rack supply unit 190 will be describedwith reference to FIG. 14 .

FIG. 14 is a perspective view illustrating the arrangement of a moldsupply unit 192 and the rack supply unit 190 which are components in theapparatus for manufacturing artificial marble 100 according to thepresent invention.

As illustrated in the drawing, the rack supply unit 190 is configured topush a plurality of molds M into the mold supply unit 192 in the rightdirection while placing the rack R accommodating and laminating thereina plurality of molds M from which artificial marbles 1 are separated,and also includes a plurality of cylinders 194 for extension andreduction.

The mold supply unit 192 allows the rack R to be pushed to the rightdirection in such a manner that the right end of the mold supply unit192 rectilinearly reciprocates in the state in which the mold supplyunit 192 is fixed to a fixed board 196.

The mold supply unit 192 is provided in the right side of the racksupply unit 190. The mold supply unit 192 has a mold accommodation space197 elongated in the vertical direction to accommodate a plurality ofmolds M therein. An elevator 198 is installed in the mold supply unit192 to move the molds M in the upward and downward direction.

An ejector 199 is provided above the rack supply unit 190 to supply themolds M, which are lifted up from the mold accommodation space 197, tothe mold guide unit 150 one by one.

The ejector 199 is configured such that the length thereof is extendedand reduced and an ejecting plate having a thickness smaller than thethickness of the mold M is provided at the right end of the ejector soas to interlock therewith, thereby pushing the mold M to the rightdirection one by one.

Accordingly, the apparatus for manufacturing artificial marble 100having the above configuration can continuously perform a series ofprocesses from the supply of the mold M to the extraction of the rack R.

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

The invention claimed is:
 1. An artificial marble manufactured by amethod comprising: supplying to a granite soil storage unit with agranite soil by storing, drying, and heating it; heating, by a granitesoil heating unit, the granite soil supplied from the granite soilstorage unit; storing, by a resin storing unit, a thermoplasticpolyurethane (TPU) resin maintained in a solid phase at roomtemperature; accommodating, by a mixing-transporting unit, the TPU resinand the heated granite soil therein and then melting and mixing them toproduce and simultaneously transport an artificial marble slurry;guiding, by a material guide unit, the granite soil and the TPU resininto the mixing-transporting unit; discharging, by a discharge unit, theartificial marble slurry mixed in the mixing-transporting unit by acertain amount; continuously supplying, by a mold supply unit, a moldfor accommodating and molding the artificial marble slurry therein;guiding, by a mold guide unit, the mold supplied from the mold supplyunit downward of the discharge unit to accommodate the artificial marbleslurry in the mold; forming, by a forming unit, the artificial marble byapplying vibration and pressure to the artificial marble slurryaccommodated in the mold; extracting, by an extraction unit, the moldaccommodating the artificial marble; and laminating and storing, by alamination unit, the mold extracted by the extraction unit, wherein thegranite soil storage unit has a dehumidification function for removingwater from the granite soil, wherein the granite soil heating unitcomprises a low temperature portion having a heating temperature of 100to 300° C., an intermediate temperature portion having a heatingtemperature of 150 to 350° C., and a high temperature portion having aheating temperature of 200 to 400° C., and the granite soil is graduallyheated to a temperature of 150 to 250° C.; and wherein the TPU resin iscoated on an outer surface of the granite soil, and the granite soil anda granite soil adjacent thereto are spaced apart from each other to forma pore.
 2. The artificial marble according to claim 1, wherein thegranite soil is protected by the TPU resin when an external force isapplied thereto, and the TPU resin generates an elastic force.
 3. Theartificial marble according to claim 1, wherein the method furthercomprises: forming, by the mixing-transporting unit, the artificialmarble slurry by melting and mixing the granite soil and the TPU resinthrough rolling by self-weight, thereby minimizing damage and abrasionof the granite soil.
 4. The artificial marble according to claim 3,wherein the method further comprises: guiding, by a granite soil flowpipe, the granite soil into the mixing-transporting unit; and guiding,by a resin flow pipe, the TPU resin into the mixing-transporting unit ina state in which it is partitioned from the granite soil flow pipe. 5.The artificial marble according to claim 4, wherein the discharge unitis narrowed in internal size toward its lower portion to collect theartificial marble slurry supplied from the mixing-transporting unit by acertain amount and then continuously discharge it by self-weight, and apressure of 0.1 to 1 kgf/cm² is applied to the artificial marble slurryduring discharge.
 6. The artificial marble according to claim 5, whereinthe method further comprises: moving, by the mold guide unit, theartificial marble slurry, which is discharged from the discharge unit,at a downward angle of 20 to 35° to guide it into the mold.
 7. Theartificial marble according to claim 6, wherein the mold guide unit hasa temporary forming part provided at one side thereof to pressurize andform the artificial marble slurry that is discharged from the dischargeunit and accommodated in the mold.
 8. The artificial marble according toclaim 7, wherein the method further comprises: laminating, by theforming unit, a plurality of molds accommodating the artificial marbleslurry to apply a load of 0.1 kgf/cm² to 1 kgf/cm² to a mold located atthe lowermost position while providing vibration to the mold, andextracting, by the extraction unit, the mold located at the lowermostposition, wherein a mold laminated at the uppermost position isextracted by the extraction unit in a state in which the artificialmarble is completed after 5 to 20 minutes.
 9. The artificial marbleaccording to claim 8, wherein the forming unit comprises: a laminationspace that is open at a portion of a side surface thereof and its upperportion for lamination of the plurality of molds; a lifter configured torectilinearly reciprocate in a vertical direction outside the laminationspace; a load removal part extended and reduced in a direction of themolds, the load removal part being coupled to one side of the lifter toremove a load applied to the lowermost mold by vertical interlocking; apedestal supporting the molds transported by a loader to laminate themolds in the lamination space, the loader allowing the mold to be seatedin the lamination space; and a vibration generator for providingvibration to the molds.
 10. The artificial marble according to claim 9,wherein the method further comprises: accommodating, by the laminationunit, a rack for laminating the plurality of molds, and moving the rackup and down by an elevation device.
 11. The artificial marble accordingto claim 10, wherein a rack supply unit is provided in the vicinity ofthe mold supply unit to supply the rack accommodating therein theplurality of molds from which the artificial marble is separated intothe mold supply unit.